fs/btrfs/super.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/blkdev.h>
  20 #include <linux/module.h>
  21 #include <linux/buffer_head.h>
  22 #include <linux/fs.h>
  23 #include <linux/pagemap.h>
  24 #include <linux/highmem.h>
  25 #include <linux/time.h>
  26 #include <linux/init.h>
  27 #include <linux/seq_file.h>
  28 #include <linux/string.h>
  29 #include <linux/backing-dev.h>
  30 #include <linux/mount.h>
  31 #include <linux/mpage.h>
  32 #include <linux/swap.h>
  33 #include <linux/writeback.h>
  34 #include <linux/statfs.h>
  35 #include <linux/compat.h>
  36 #include <linux/parser.h>
  37 #include <linux/ctype.h>
  38 #include <linux/namei.h>
  39 #include <linux/miscdevice.h>
  40 #include <linux/magic.h>
  41 #include <linux/slab.h>
  42 #include <linux/cleancache.h>
  43 #include <linux/ratelimit.h>
  44 #include <linux/btrfs.h>
  45 #include "delayed-inode.h"
  46 #include "ctree.h"
  47 #include "disk-io.h"
  48 #include "transaction.h"
  49 #include "btrfs_inode.h"
  50 #include "print-tree.h"
  51 #include "xattr.h"
  52 #include "volumes.h"
  53 #include "export.h"
  54 #include "compression.h"
  55 #include "rcu-string.h"
  56 #include "dev-replace.h"
  57 #include "free-space-cache.h"
  58 #include "backref.h"
  59 #include "tests/btrfs-tests.h"
  60
  61 #define CREATE_TRACE_POINTS
  62 #include <trace/events/btrfs.h>
  63
  64 static const struct super_operations btrfs_super_ops;
  65 static struct file_system_type btrfs_fs_type;
  66
  67 static const char *btrfs_decode_error(int errno)
  68 {
  69         char *errstr = "unknown";
  70
  71         switch (errno) {
  72         case -EIO:
  73                 errstr = "IO failure";
  74                 break;
  75         case -ENOMEM:
  76                 errstr = "Out of memory";
  77                 break;
  78         case -EROFS:
  79                 errstr = "Readonly filesystem";
  80                 break;
  81         case -EEXIST:
  82                 errstr = "Object already exists";
  83                 break;
  84         case -ENOSPC:
  85                 errstr = "No space left";
  86                 break;
  87         case -ENOENT:
  88                 errstr = "No such entry";
  89                 break;
  90         }
  91
  92         return errstr;
  93 }
  94
  95 static void save_error_info(struct btrfs_fs_info *fs_info)
  96 {
  97         /*
  98          * today we only save the error info into ram.  Long term we'll
  99          * also send it down to the disk
 100          */
 101         set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
 102 }
 103
 104 /* btrfs handle error by forcing the filesystem readonly */
 105 static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
 106 {
 107         struct super_block *sb = fs_info->sb;
 108
 109         if (sb->s_flags & MS_RDONLY)
 110                 return;
 111
 112         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
 113                 sb->s_flags |= MS_RDONLY;
 114                 btrfs_info(fs_info, "forced readonly");
 115                 /*
 116                  * Note that a running device replace operation is not
 117                  * canceled here although there is no way to update
 118                  * the progress. It would add the risk of a deadlock,
 119                  * therefore the canceling is ommited. The only penalty
 120                  * is that some I/O remains active until the procedure
 121                  * completes. The next time when the filesystem is
 122                  * mounted writeable again, the device replace
 123                  * operation continues.
 124                  */
 125         }
 126 }
 127
 128 #ifdef CONFIG_PRINTK
 129 /*
 130  * __btrfs_std_error decodes expected errors from the caller and
 131  * invokes the approciate error response.
 132  */
 133 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
 134                        unsigned int line, int errno, const char *fmt, ...)
 135 {
 136         struct super_block *sb = fs_info->sb;
 137         const char *errstr;
 138
 139         /*
 140          * Special case: if the error is EROFS, and we're already
 141          * under MS_RDONLY, then it is safe here.
 142          */
 143         if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
 144                 return;
 145
 146         errstr = btrfs_decode_error(errno);
 147         if (fmt) {
 148                 struct va_format vaf;
 149                 va_list args;
 150
 151                 va_start(args, fmt);
 152                 vaf.fmt = fmt;
 153                 vaf.va = &args;
 154
 155                 printk(KERN_CRIT
 156                         "BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
 157                         sb->s_id, function, line, errno, errstr, &vaf);
 158                 va_end(args);
 159         } else {
 160                 printk(KERN_CRIT "BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
 161                         sb->s_id, function, line, errno, errstr);
 162         }
 163
 164         /* Don't go through full error handling during mount */
 165         save_error_info(fs_info);
 166         if (sb->s_flags & MS_BORN)
 167                 btrfs_handle_error(fs_info);
 168 }
 169
 170 static const char * const logtypes[] = {
 171         "emergency",
 172         "alert",
 173         "critical",
 174         "error",
 175         "warning",
 176         "notice",
 177         "info",
 178         "debug",
 179 };
 180
 181 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
 182 {
 183         struct super_block *sb = fs_info->sb;
 184         char lvl[4];
 185         struct va_format vaf;
 186         va_list args;
 187         const char *type = logtypes[4];
 188         int kern_level;
 189
 190         va_start(args, fmt);
 191
 192         kern_level = printk_get_level(fmt);
 193         if (kern_level) {
 194                 size_t size = printk_skip_level(fmt) - fmt;
 195                 memcpy(lvl, fmt,  size);
 196                 lvl[size] = '\0';
 197                 fmt += size;
 198                 type = logtypes[kern_level - '0'];
 199         } else
 200                 *lvl = '\0';
 201
 202         vaf.fmt = fmt;
 203         vaf.va = &args;
 204
 205         printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
 206
 207         va_end(args);
 208 }
 209
 210 #else
 211
 212 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
 213                        unsigned int line, int errno, const char *fmt, ...)
 214 {
 215         struct super_block *sb = fs_info->sb;
 216
 217         /*
 218          * Special case: if the error is EROFS, and we're already
 219          * under MS_RDONLY, then it is safe here.
 220          */
 221         if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
 222                 return;
 223
 224         /* Don't go through full error handling during mount */
 225         if (sb->s_flags & MS_BORN) {
 226                 save_error_info(fs_info);
 227                 btrfs_handle_error(fs_info);
 228         }
 229 }
 230 #endif
 231
 232 /*
 233  * We only mark the transaction aborted and then set the file system read-only.
 234  * This will prevent new transactions from starting or trying to join this
 235  * one.
 236  *
 237  * This means that error recovery at the call site is limited to freeing
 238  * any local memory allocations and passing the error code up without
 239  * further cleanup. The transaction should complete as it normally would
 240  * in the call path but will return -EIO.
 241  *
 242  * We'll complete the cleanup in btrfs_end_transaction and
 243  * btrfs_commit_transaction.
 244  */
 245 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
 246                                struct btrfs_root *root, const char *function,
 247                                unsigned int line, int errno)
 248 {
 249         /*
 250          * Report first abort since mount
 251          */
 252         if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED,
 253                                 &root->fs_info->fs_state)) {
 254                 WARN(1, KERN_DEBUG "BTRFS: Transaction aborted (error %d)\n",
 255                                 errno);
 256         }
 257         trans->aborted = errno;
 258         /* Nothing used. The other threads that have joined this
 259          * transaction may be able to continue. */
 260         if (!trans->blocks_used) {
 261                 const char *errstr;
 262
 263                 errstr = btrfs_decode_error(errno);
 264                 btrfs_warn(root->fs_info,
 265                            "%s:%d: Aborting unused transaction(%s).",
 266                            function, line, errstr);
 267                 return;
 268         }
 269         ACCESS_ONCE(trans->transaction->aborted) = errno;
 270         /* Wake up anybody who may be waiting on this transaction */
 271         wake_up(&root->fs_info->transaction_wait);
 272         wake_up(&root->fs_info->transaction_blocked_wait);
 273         __btrfs_std_error(root->fs_info, function, line, errno, NULL);
 274 }
 275 /*
 276  * __btrfs_panic decodes unexpected, fatal errors from the caller,
 277  * issues an alert, and either panics or BUGs, depending on mount options.
 278  */
 279 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
 280                    unsigned int line, int errno, const char *fmt, ...)
 281 {
 282         char *s_id = "<unknown>";
 283         const char *errstr;
 284         struct va_format vaf = { .fmt = fmt };
 285         va_list args;
 286
 287         if (fs_info)
 288                 s_id = fs_info->sb->s_id;
 289
 290         va_start(args, fmt);
 291         vaf.va = &args;
 292
 293         errstr = btrfs_decode_error(errno);
 294         if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
 295                 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
 296                         s_id, function, line, &vaf, errno, errstr);
 297
 298         btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
 299                    function, line, &vaf, errno, errstr);
 300         va_end(args);
 301         /* Caller calls BUG() */
 302 }
 303
 304 static void btrfs_put_super(struct super_block *sb)
 305 {
 306         (void)close_ctree(btrfs_sb(sb)->tree_root);
 307         /* FIXME: need to fix VFS to return error? */
 308         /* AV: return it _where_?  ->put_super() can be triggered by any number
 309          * of async events, up to and including delivery of SIGKILL to the
 310          * last process that kept it busy.  Or segfault in the aforementioned
 311          * process...  Whom would you report that to?
 312          */
 313 }
 314
 315 enum {
 316         Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
 317         Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
 318         Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
 319         Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
 320         Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
 321         Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
 322         Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
 323         Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
 324         Opt_check_integrity, Opt_check_integrity_including_extent_data,
 325         Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree,
 326         Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard,
 327         Opt_noenospc_debug, Opt_noflushoncommit,
 328         Opt_err,
 329 };
 330
 331 static match_table_t tokens = {
 332         {Opt_degraded, "degraded"},
 333         {Opt_subvol, "subvol=%s"},
 334         {Opt_subvolid, "subvolid=%s"},
 335         {Opt_device, "device=%s"},
 336         {Opt_nodatasum, "nodatasum"},
 337         {Opt_nodatacow, "nodatacow"},
 338         {Opt_nobarrier, "nobarrier"},
 339         {Opt_barrier, "barrier"},
 340         {Opt_max_inline, "max_inline=%s"},
 341         {Opt_alloc_start, "alloc_start=%s"},
 342         {Opt_thread_pool, "thread_pool=%d"},
 343         {Opt_compress, "compress"},
 344         {Opt_compress_type, "compress=%s"},
 345         {Opt_compress_force, "compress-force"},
 346         {Opt_compress_force_type, "compress-force=%s"},
 347         {Opt_ssd, "ssd"},
 348         {Opt_ssd_spread, "ssd_spread"},
 349         {Opt_nossd, "nossd"},
 350         {Opt_noacl, "noacl"},
 351         {Opt_notreelog, "notreelog"},
 352         {Opt_flushoncommit, "flushoncommit"},
 353         {Opt_noflushoncommit, "noflushoncommit"},
 354         {Opt_ratio, "metadata_ratio=%d"},
 355         {Opt_discard, "discard"},
 356         {Opt_nodiscard, "nodiscard"},
 357         {Opt_space_cache, "space_cache"},
 358         {Opt_clear_cache, "clear_cache"},
 359         {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
 360         {Opt_enospc_debug, "enospc_debug"},
 361         {Opt_noenospc_debug, "noenospc_debug"},
 362         {Opt_subvolrootid, "subvolrootid=%d"},
 363         {Opt_defrag, "autodefrag"},
 364         {Opt_nodefrag, "noautodefrag"},
 365         {Opt_inode_cache, "inode_cache"},
 366         {Opt_no_space_cache, "nospace_cache"},
 367         {Opt_recovery, "recovery"},
 368         {Opt_skip_balance, "skip_balance"},
 369         {Opt_check_integrity, "check_int"},
 370         {Opt_check_integrity_including_extent_data, "check_int_data"},
 371         {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
 372         {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
 373         {Opt_fatal_errors, "fatal_errors=%s"},
 374         {Opt_commit_interval, "commit=%d"},
 375         {Opt_err, NULL},
 376 };
 377
 378 /*
 379  * Regular mount options parser.  Everything that is needed only when
 380  * reading in a new superblock is parsed here.
 381  * XXX JDM: This needs to be cleaned up for remount.
 382  */
 383 int btrfs_parse_options(struct btrfs_root *root, char *options)
 384 {
 385         struct btrfs_fs_info *info = root->fs_info;
 386         substring_t args[MAX_OPT_ARGS];
 387         char *p, *num, *orig = NULL;
 388         u64 cache_gen;
 389         int intarg;
 390         int ret = 0;
 391         char *compress_type;
 392         bool compress_force = false;
 393
 394         cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
 395         if (cache_gen)
 396                 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
 397
 398         if (!options)
 399                 goto out;
 400
 401         /*
 402          * strsep changes the string, duplicate it because parse_options
 403          * gets called twice
 404          */
 405         options = kstrdup(options, GFP_NOFS);
 406         if (!options)
 407                 return -ENOMEM;
 408
 409         orig = options;
 410
 411         while ((p = strsep(&options, ",")) != NULL) {
 412                 int token;
 413                 if (!*p)
 414                         continue;
 415
 416                 token = match_token(p, tokens, args);
 417                 switch (token) {
 418                 case Opt_degraded:
 419                         btrfs_info(root->fs_info, "allowing degraded mounts");
 420                         btrfs_set_opt(info->mount_opt, DEGRADED);
 421                         break;
 422                 case Opt_subvol:
 423                 case Opt_subvolid:
 424                 case Opt_subvolrootid:
 425                 case Opt_device:
 426                         /*
 427                          * These are parsed by btrfs_parse_early_options
 428                          * and can be happily ignored here.
 429                          */
 430                         break;
 431                 case Opt_nodatasum:
 432                         btrfs_info(root->fs_info, "setting nodatasum");
 433                         btrfs_set_opt(info->mount_opt, NODATASUM);
 434                         break;
 435                 case Opt_nodatacow:
 436                         if (!btrfs_test_opt(root, COMPRESS) ||
 437                                 !btrfs_test_opt(root, FORCE_COMPRESS)) {
 438                                         btrfs_info(root->fs_info,
 439                                                 "setting nodatacow, compression disabled");
 440                         } else {
 441                                 btrfs_info(root->fs_info, "setting nodatacow");
 442                         }
 443                         btrfs_clear_opt(info->mount_opt, COMPRESS);
 444                         btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
 445                         btrfs_set_opt(info->mount_opt, NODATACOW);
 446                         btrfs_set_opt(info->mount_opt, NODATASUM);
 447                         break;
 448                 case Opt_compress_force:
 449                 case Opt_compress_force_type:
 450                         compress_force = true;
 451                         /* Fallthrough */
 452                 case Opt_compress:
 453                 case Opt_compress_type:
 454                         if (token == Opt_compress ||
 455                             token == Opt_compress_force ||
 456                             strcmp(args[0].from, "zlib") == 0) {
 457                                 compress_type = "zlib";
 458                                 info->compress_type = BTRFS_COMPRESS_ZLIB;
 459                                 btrfs_set_opt(info->mount_opt, COMPRESS);
 460                                 btrfs_clear_opt(info->mount_opt, NODATACOW);
 461                                 btrfs_clear_opt(info->mount_opt, NODATASUM);
 462                         } else if (strcmp(args[0].from, "lzo") == 0) {
 463                                 compress_type = "lzo";
 464                                 info->compress_type = BTRFS_COMPRESS_LZO;
 465                                 btrfs_set_opt(info->mount_opt, COMPRESS);
 466                                 btrfs_clear_opt(info->mount_opt, NODATACOW);
 467                                 btrfs_clear_opt(info->mount_opt, NODATASUM);
 468                                 btrfs_set_fs_incompat(info, COMPRESS_LZO);
 469                         } else if (strncmp(args[0].from, "no", 2) == 0) {
 470                                 compress_type = "no";
 471                                 btrfs_clear_opt(info->mount_opt, COMPRESS);
 472                                 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
 473                                 compress_force = false;
 474                         } else {
 475                                 ret = -EINVAL;
 476                                 goto out;
 477                         }
 478
 479                         if (compress_force) {
 480                                 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
 481                                 btrfs_info(root->fs_info, "force %s compression",
 482                                         compress_type);
 483                         } else if (btrfs_test_opt(root, COMPRESS)) {
 484                                 pr_info("btrfs: use %s compression\n",
 485                                         compress_type);
 486                         }
 487                         break;
 488                 case Opt_ssd:
 489                         btrfs_info(root->fs_info, "use ssd allocation scheme");
 490                         btrfs_set_opt(info->mount_opt, SSD);
 491                         break;
 492                 case Opt_ssd_spread:
 493                         btrfs_info(root->fs_info, "use spread ssd allocation scheme");
 494                         btrfs_set_opt(info->mount_opt, SSD);
 495                         btrfs_set_opt(info->mount_opt, SSD_SPREAD);
 496                         break;
 497                 case Opt_nossd:
 498                         btrfs_info(root->fs_info, "not using ssd allocation scheme");
 499                         btrfs_set_opt(info->mount_opt, NOSSD);
 500                         btrfs_clear_opt(info->mount_opt, SSD);
 501                         btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
 502                         break;
 503                 case Opt_barrier:
 504                         if (btrfs_test_opt(root, NOBARRIER))
 505                                 btrfs_info(root->fs_info, "turning on barriers");
 506                         btrfs_clear_opt(info->mount_opt, NOBARRIER);
 507                         break;
 508                 case Opt_nobarrier:
 509                         btrfs_info(root->fs_info, "turning off barriers");
 510                         btrfs_set_opt(info->mount_opt, NOBARRIER);
 511                         break;
 512                 case Opt_thread_pool:
 513                         ret = match_int(&args[0], &intarg);
 514                         if (ret) {
 515                                 goto out;
 516                         } else if (intarg > 0) {
 517                                 info->thread_pool_size = intarg;
 518                         } else {
 519                                 ret = -EINVAL;
 520                                 goto out;
 521                         }
 522                         break;
 523                 case Opt_max_inline:
 524                         num = match_strdup(&args[0]);
 525                         if (num) {
 526                                 info->max_inline = memparse(num, NULL);
 527                                 kfree(num);
 528
 529                                 if (info->max_inline) {
 530                                         info->max_inline = max_t(u64,
 531                                                 info->max_inline,
 532                                                 root->sectorsize);
 533                                 }
 534                                 btrfs_info(root->fs_info, "max_inline at %llu",
 535                                         info->max_inline);
 536                         } else {
 537                                 ret = -ENOMEM;
 538                                 goto out;
 539                         }
 540                         break;
 541                 case Opt_alloc_start:
 542                         num = match_strdup(&args[0]);
 543                         if (num) {
 544                                 mutex_lock(&info->chunk_mutex);
 545                                 info->alloc_start = memparse(num, NULL);
 546                                 mutex_unlock(&info->chunk_mutex);
 547                                 kfree(num);
 548                                 btrfs_info(root->fs_info, "allocations start at %llu",
 549                                         info->alloc_start);
 550                         } else {
 551                                 ret = -ENOMEM;
 552                                 goto out;
 553                         }
 554                         break;
 555                 case Opt_noacl:
 556                         root->fs_info->sb->s_flags &= ~MS_POSIXACL;
 557                         break;
 558                 case Opt_notreelog:
 559                         btrfs_info(root->fs_info, "disabling tree log");
 560                         btrfs_set_opt(info->mount_opt, NOTREELOG);
 561                         break;
 562                 case Opt_flushoncommit:
 563                         btrfs_info(root->fs_info, "turning on flush-on-commit");
 564                         btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
 565                         break;
 566                 case Opt_noflushoncommit:
 567                         if (btrfs_test_opt(root, FLUSHONCOMMIT))
 568                                 btrfs_info(root->fs_info, "turning off flush-on-commit");
 569                         btrfs_clear_opt(info->mount_opt, FLUSHONCOMMIT);
 570                         break;
 571                 case Opt_ratio:
 572                         ret = match_int(&args[0], &intarg);
 573                         if (ret) {
 574                                 goto out;
 575                         } else if (intarg >= 0) {
 576                                 info->metadata_ratio = intarg;
 577                                 btrfs_info(root->fs_info, "metadata ratio %d",
 578                                        info->metadata_ratio);
 579                         } else {
 580                                 ret = -EINVAL;
 581                                 goto out;
 582                         }
 583                         break;
 584                 case Opt_discard:
 585                         btrfs_set_opt(info->mount_opt, DISCARD);
 586                         break;
 587                 case Opt_nodiscard:
 588                         btrfs_clear_opt(info->mount_opt, DISCARD);
 589                         break;
 590                 case Opt_space_cache:
 591                         btrfs_set_opt(info->mount_opt, SPACE_CACHE);
 592                         break;
 593                 case Opt_rescan_uuid_tree:
 594                         btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
 595                         break;
 596                 case Opt_no_space_cache:
 597                         btrfs_info(root->fs_info, "disabling disk space caching");
 598                         btrfs_clear_opt(info->mount_opt, SPACE_CACHE);
 599                         break;
 600                 case Opt_inode_cache:
 601                         btrfs_info(root->fs_info, "enabling inode map caching");
 602                         btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
 603                         break;
 604                 case Opt_clear_cache:
 605                         btrfs_info(root->fs_info, "force clearing of disk cache");
 606                         btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
 607                         break;
 608                 case Opt_user_subvol_rm_allowed:
 609                         btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
 610                         break;
 611                 case Opt_enospc_debug:
 612                         btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
 613                         break;
 614                 case Opt_noenospc_debug:
 615                         btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
 616                         break;
 617                 case Opt_defrag:
 618                         btrfs_info(root->fs_info, "enabling auto defrag");
 619                         btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
 620                         break;
 621                 case Opt_nodefrag:
 622                         if (btrfs_test_opt(root, AUTO_DEFRAG))
 623                                 btrfs_info(root->fs_info, "disabling auto defrag");
 624                         btrfs_clear_opt(info->mount_opt, AUTO_DEFRAG);
 625                         break;
 626                 case Opt_recovery:
 627                         btrfs_info(root->fs_info, "enabling auto recovery");
 628                         btrfs_set_opt(info->mount_opt, RECOVERY);
 629                         break;
 630                 case Opt_skip_balance:
 631                         btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
 632                         break;
 633 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
 634                 case Opt_check_integrity_including_extent_data:
 635                         btrfs_info(root->fs_info,
 636                                    "enabling check integrity including extent data");
 637                         btrfs_set_opt(info->mount_opt,
 638                                       CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
 639                         btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
 640                         break;
 641                 case Opt_check_integrity:
 642                         btrfs_info(root->fs_info, "enabling check integrity");
 643                         btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
 644                         break;
 645                 case Opt_check_integrity_print_mask:
 646                         ret = match_int(&args[0], &intarg);
 647                         if (ret) {
 648                                 goto out;
 649                         } else if (intarg >= 0) {
 650                                 info->check_integrity_print_mask = intarg;
 651                                 btrfs_info(root->fs_info, "check_integrity_print_mask 0x%x",
 652                                        info->check_integrity_print_mask);
 653                         } else {
 654                                 ret = -EINVAL;
 655                                 goto out;
 656                         }
 657                         break;
 658 #else
 659                 case Opt_check_integrity_including_extent_data:
 660                 case Opt_check_integrity:
 661                 case Opt_check_integrity_print_mask:
 662                         btrfs_err(root->fs_info,
 663                                 "support for check_integrity* not compiled in!");
 664                         ret = -EINVAL;
 665                         goto out;
 666 #endif
 667                 case Opt_fatal_errors:
 668                         if (strcmp(args[0].from, "panic") == 0)
 669                                 btrfs_set_opt(info->mount_opt,
 670                                               PANIC_ON_FATAL_ERROR);
 671                         else if (strcmp(args[0].from, "bug") == 0)
 672                                 btrfs_clear_opt(info->mount_opt,
 673                                               PANIC_ON_FATAL_ERROR);
 674                         else {
 675                                 ret = -EINVAL;
 676                                 goto out;
 677                         }
 678                         break;
 679                 case Opt_commit_interval:
 680                         intarg = 0;
 681                         ret = match_int(&args[0], &intarg);
 682                         if (ret < 0) {
 683                                 btrfs_err(root->fs_info, "invalid commit interval");
 684                                 ret = -EINVAL;
 685                                 goto out;
 686                         }
 687                         if (intarg > 0) {
 688                                 if (intarg > 300) {
 689                                         btrfs_warn(root->fs_info, "excessive commit interval %d",
 690                                                         intarg);
 691                                 }
 692                                 info->commit_interval = intarg;
 693                         } else {
 694                                 btrfs_info(root->fs_info, "using default commit interval %ds",
 695                                     BTRFS_DEFAULT_COMMIT_INTERVAL);
 696                                 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
 697                         }
 698                         break;
 699                 case Opt_err:
 700                         btrfs_info(root->fs_info, "unrecognized mount option '%s'", p);
 701                         ret = -EINVAL;
 702                         goto out;
 703                 default:
 704                         break;
 705                 }
 706         }
 707 out:
 708         if (!ret && btrfs_test_opt(root, SPACE_CACHE))
 709                 btrfs_info(root->fs_info, "disk space caching is enabled");
 710         kfree(orig);
 711         return ret;
 712 }
 713
 714 /*
 715  * Parse mount options that are required early in the mount process.
 716  *
 717  * All other options will be parsed on much later in the mount process and
 718  * only when we need to allocate a new super block.
 719  */
 720 static int btrfs_parse_early_options(const char *options, fmode_t flags,
 721                 void *holder, char **subvol_name, u64 *subvol_objectid,
 722                 struct btrfs_fs_devices **fs_devices)
 723 {
 724         substring_t args[MAX_OPT_ARGS];
 725         char *device_name, *opts, *orig, *p;
 726         char *num = NULL;
 727         int error = 0;
 728
 729         if (!options)
 730                 return 0;
 731
 732         /*
 733          * strsep changes the string, duplicate it because parse_options
 734          * gets called twice
 735          */
 736         opts = kstrdup(options, GFP_KERNEL);
 737         if (!opts)
 738                 return -ENOMEM;
 739         orig = opts;
 740
 741         while ((p = strsep(&opts, ",")) != NULL) {
 742                 int token;
 743                 if (!*p)
 744                         continue;
 745
 746                 token = match_token(p, tokens, args);
 747                 switch (token) {
 748                 case Opt_subvol:
 749                         kfree(*subvol_name);
 750                         *subvol_name = match_strdup(&args[0]);
 751                         if (!*subvol_name) {
 752                                 error = -ENOMEM;
 753                                 goto out;
 754                         }
 755                         break;
 756                 case Opt_subvolid:
 757                         num = match_strdup(&args[0]);
 758                         if (num) {
 759                                 *subvol_objectid = memparse(num, NULL);
 760                                 kfree(num);
 761                                 /* we want the original fs_tree */
 762                                 if (!*subvol_objectid)
 763                                         *subvol_objectid =
 764                                                 BTRFS_FS_TREE_OBJECTID;
 765                         } else {
 766                                 error = -EINVAL;
 767                                 goto out;
 768                         }
 769                         break;
 770                 case Opt_subvolrootid:
 771                         printk(KERN_WARNING
 772                                 "BTRFS: 'subvolrootid' mount option is deprecated and has "
 773                                 "no effect\n");
 774                         break;
 775                 case Opt_device:
 776                         device_name = match_strdup(&args[0]);
 777                         if (!device_name) {
 778                                 error = -ENOMEM;
 779                                 goto out;
 780                         }
 781                         error = btrfs_scan_one_device(device_name,
 782                                         flags, holder, fs_devices);
 783                         kfree(device_name);
 784                         if (error)
 785                                 goto out;
 786                         break;
 787                 default:
 788                         break;
 789                 }
 790         }
 791
 792 out:
 793         kfree(orig);
 794         return error;
 795 }
 796
 797 static struct dentry *get_default_root(struct super_block *sb,
 798                                        u64 subvol_objectid)
 799 {
 800         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 801         struct btrfs_root *root = fs_info->tree_root;
 802         struct btrfs_root *new_root;
 803         struct btrfs_dir_item *di;
 804         struct btrfs_path *path;
 805         struct btrfs_key location;
 806         struct inode *inode;
 807         u64 dir_id;
 808         int new = 0;
 809
 810         /*
 811          * We have a specific subvol we want to mount, just setup location and
 812          * go look up the root.
 813          */
 814         if (subvol_objectid) {
 815                 location.objectid = subvol_objectid;
 816                 location.type = BTRFS_ROOT_ITEM_KEY;
 817                 location.offset = (u64)-1;
 818                 goto find_root;
 819         }
 820
 821         path = btrfs_alloc_path();
 822         if (!path)
 823                 return ERR_PTR(-ENOMEM);
 824         path->leave_spinning = 1;
 825
 826         /*
 827          * Find the "default" dir item which points to the root item that we
 828          * will mount by default if we haven't been given a specific subvolume
 829          * to mount.
 830          */
 831         dir_id = btrfs_super_root_dir(fs_info->super_copy);
 832         di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
 833         if (IS_ERR(di)) {
 834                 btrfs_free_path(path);
 835                 return ERR_CAST(di);
 836         }
 837         if (!di) {
 838                 /*
 839                  * Ok the default dir item isn't there.  This is weird since
 840                  * it's always been there, but don't freak out, just try and
 841                  * mount to root most subvolume.
 842                  */
 843                 btrfs_free_path(path);
 844                 dir_id = BTRFS_FIRST_FREE_OBJECTID;
 845                 new_root = fs_info->fs_root;
 846                 goto setup_root;
 847         }
 848
 849         btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
 850         btrfs_free_path(path);
 851
 852 find_root:
 853         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
 854         if (IS_ERR(new_root))
 855                 return ERR_CAST(new_root);
 856
 857         dir_id = btrfs_root_dirid(&new_root->root_item);
 858 setup_root:
 859         location.objectid = dir_id;
 860         location.type = BTRFS_INODE_ITEM_KEY;
 861         location.offset = 0;
 862
 863         inode = btrfs_iget(sb, &location, new_root, &new);
 864         if (IS_ERR(inode))
 865                 return ERR_CAST(inode);
 866
 867         /*
 868          * If we're just mounting the root most subvol put the inode and return
 869          * a reference to the dentry.  We will have already gotten a reference
 870          * to the inode in btrfs_fill_super so we're good to go.
 871          */
 872         if (!new && sb->s_root->d_inode == inode) {
 873                 iput(inode);
 874                 return dget(sb->s_root);
 875         }
 876
 877         return d_obtain_alias(inode);
 878 }
 879
 880 static int btrfs_fill_super(struct super_block *sb,
 881                             struct btrfs_fs_devices *fs_devices,
 882                             void *data, int silent)
 883 {
 884         struct inode *inode;
 885         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 886         struct btrfs_key key;
 887         int err;
 888
 889         sb->s_maxbytes = MAX_LFS_FILESIZE;
 890         sb->s_magic = BTRFS_SUPER_MAGIC;
 891         sb->s_op = &btrfs_super_ops;
 892         sb->s_d_op = &btrfs_dentry_operations;
 893         sb->s_export_op = &btrfs_export_ops;
 894         sb->s_xattr = btrfs_xattr_handlers;
 895         sb->s_time_gran = 1;
 896 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
 897         sb->s_flags |= MS_POSIXACL;
 898 #endif
 899         sb->s_flags |= MS_I_VERSION;
 900         err = open_ctree(sb, fs_devices, (char *)data);
 901         if (err) {
 902                 printk(KERN_ERR "BTRFS: open_ctree failed\n");
 903                 return err;
 904         }
 905
 906         key.objectid = BTRFS_FIRST_FREE_OBJECTID;
 907         key.type = BTRFS_INODE_ITEM_KEY;
 908         key.offset = 0;
 909         inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
 910         if (IS_ERR(inode)) {
 911                 err = PTR_ERR(inode);
 912                 goto fail_close;
 913         }
 914
 915         sb->s_root = d_make_root(inode);
 916         if (!sb->s_root) {
 917                 err = -ENOMEM;
 918                 goto fail_close;
 919         }
 920
 921         save_mount_options(sb, data);
 922         cleancache_init_fs(sb);
 923         sb->s_flags |= MS_ACTIVE;
 924         return 0;
 925
 926 fail_close:
 927         close_ctree(fs_info->tree_root);
 928         return err;
 929 }
 930
 931 int btrfs_sync_fs(struct super_block *sb, int wait)
 932 {
 933         struct btrfs_trans_handle *trans;
 934         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 935         struct btrfs_root *root = fs_info->tree_root;
 936
 937         trace_btrfs_sync_fs(wait);
 938
 939         if (!wait) {
 940                 filemap_flush(fs_info->btree_inode->i_mapping);
 941                 return 0;
 942         }
 943
 944         btrfs_wait_ordered_roots(fs_info, -1);
 945
 946         trans = btrfs_attach_transaction_barrier(root);
 947         if (IS_ERR(trans)) {
 948                 /* no transaction, don't bother */
 949                 if (PTR_ERR(trans) == -ENOENT)
 950                         return 0;
 951                 return PTR_ERR(trans);
 952         }
 953         return btrfs_commit_transaction(trans, root);
 954 }
 955
 956 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
 957 {
 958         struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
 959         struct btrfs_root *root = info->tree_root;
 960         char *compress_type;
 961
 962         if (btrfs_test_opt(root, DEGRADED))
 963                 seq_puts(seq, ",degraded");
 964         if (btrfs_test_opt(root, NODATASUM))
 965                 seq_puts(seq, ",nodatasum");
 966         if (btrfs_test_opt(root, NODATACOW))
 967                 seq_puts(seq, ",nodatacow");
 968         if (btrfs_test_opt(root, NOBARRIER))
 969                 seq_puts(seq, ",nobarrier");
 970         if (info->max_inline != 8192 * 1024)
 971                 seq_printf(seq, ",max_inline=%llu", info->max_inline);
 972         if (info->alloc_start != 0)
 973                 seq_printf(seq, ",alloc_start=%llu", info->alloc_start);
 974         if (info->thread_pool_size !=  min_t(unsigned long,
 975                                              num_online_cpus() + 2, 8))
 976                 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
 977         if (btrfs_test_opt(root, COMPRESS)) {
 978                 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
 979                         compress_type = "zlib";
 980                 else
 981                         compress_type = "lzo";
 982                 if (btrfs_test_opt(root, FORCE_COMPRESS))
 983                         seq_printf(seq, ",compress-force=%s", compress_type);
 984                 else
 985                         seq_printf(seq, ",compress=%s", compress_type);
 986         }
 987         if (btrfs_test_opt(root, NOSSD))
 988                 seq_puts(seq, ",nossd");
 989         if (btrfs_test_opt(root, SSD_SPREAD))
 990                 seq_puts(seq, ",ssd_spread");
 991         else if (btrfs_test_opt(root, SSD))
 992                 seq_puts(seq, ",ssd");
 993         if (btrfs_test_opt(root, NOTREELOG))
 994                 seq_puts(seq, ",notreelog");
 995         if (btrfs_test_opt(root, FLUSHONCOMMIT))
 996                 seq_puts(seq, ",flushoncommit");
 997         if (btrfs_test_opt(root, DISCARD))
 998                 seq_puts(seq, ",discard");
 999         if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
1000                 seq_puts(seq, ",noacl");
1001         if (btrfs_test_opt(root, SPACE_CACHE))
1002                 seq_puts(seq, ",space_cache");
1003         else
1004                 seq_puts(seq, ",nospace_cache");
1005         if (btrfs_test_opt(root, RESCAN_UUID_TREE))
1006                 seq_puts(seq, ",rescan_uuid_tree");
1007         if (btrfs_test_opt(root, CLEAR_CACHE))
1008                 seq_puts(seq, ",clear_cache");
1009         if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1010                 seq_puts(seq, ",user_subvol_rm_allowed");
1011         if (btrfs_test_opt(root, ENOSPC_DEBUG))
1012                 seq_puts(seq, ",enospc_debug");
1013         if (btrfs_test_opt(root, AUTO_DEFRAG))
1014                 seq_puts(seq, ",autodefrag");
1015         if (btrfs_test_opt(root, INODE_MAP_CACHE))
1016                 seq_puts(seq, ",inode_cache");
1017         if (btrfs_test_opt(root, SKIP_BALANCE))
1018                 seq_puts(seq, ",skip_balance");
1019         if (btrfs_test_opt(root, RECOVERY))
1020                 seq_puts(seq, ",recovery");
1021 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1022         if (btrfs_test_opt(root, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1023                 seq_puts(seq, ",check_int_data");
1024         else if (btrfs_test_opt(root, CHECK_INTEGRITY))
1025                 seq_puts(seq, ",check_int");
1026         if (info->check_integrity_print_mask)
1027                 seq_printf(seq, ",check_int_print_mask=%d",
1028                                 info->check_integrity_print_mask);
1029 #endif
1030         if (info->metadata_ratio)
1031                 seq_printf(seq, ",metadata_ratio=%d",
1032                                 info->metadata_ratio);
1033         if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
1034                 seq_puts(seq, ",fatal_errors=panic");
1035         if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1036                 seq_printf(seq, ",commit=%d", info->commit_interval);
1037         return 0;
1038 }
1039
1040 static int btrfs_test_super(struct super_block *s, void *data)
1041 {
1042         struct btrfs_fs_info *p = data;
1043         struct btrfs_fs_info *fs_info = btrfs_sb(s);
1044
1045         return fs_info->fs_devices == p->fs_devices;
1046 }
1047
1048 static int btrfs_set_super(struct super_block *s, void *data)
1049 {
1050         int err = set_anon_super(s, data);
1051         if (!err)
1052                 s->s_fs_info = data;
1053         return err;
1054 }
1055
1056 /*
1057  * subvolumes are identified by ino 256
1058  */
1059 static inline int is_subvolume_inode(struct inode *inode)
1060 {
1061         if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1062                 return 1;
1063         return 0;
1064 }
1065
1066 /*
1067  * This will strip out the subvol=%s argument for an argument string and add
1068  * subvolid=0 to make sure we get the actual tree root for path walking to the
1069  * subvol we want.
1070  */
1071 static char *setup_root_args(char *args)
1072 {
1073         unsigned len = strlen(args) + 2 + 1;
1074         char *src, *dst, *buf;
1075
1076         /*
1077          * We need the same args as before, but with this substitution:
1078          * s!subvol=[^,]+!subvolid=0!
1079          *
1080          * Since the replacement string is up to 2 bytes longer than the
1081          * original, allocate strlen(args) + 2 + 1 bytes.
1082          */
1083
1084         src = strstr(args, "subvol=");
1085         /* This shouldn't happen, but just in case.. */
1086         if (!src)
1087                 return NULL;
1088
1089         buf = dst = kmalloc(len, GFP_NOFS);
1090         if (!buf)
1091                 return NULL;
1092
1093         /*
1094          * If the subvol= arg is not at the start of the string,
1095          * copy whatever precedes it into buf.
1096          */
1097         if (src != args) {
1098                 *src++ = '\0';
1099                 strcpy(buf, args);
1100                 dst += strlen(args);
1101         }
1102
1103         strcpy(dst, "subvolid=0");
1104         dst += strlen("subvolid=0");
1105
1106         /*
1107          * If there is a "," after the original subvol=... string,
1108          * copy that suffix into our buffer.  Otherwise, we're done.
1109          */
1110         src = strchr(src, ',');
1111         if (src)
1112                 strcpy(dst, src);
1113
1114         return buf;
1115 }
1116
1117 static struct dentry *mount_subvol(const char *subvol_name, int flags,
1118                                    const char *device_name, char *data)
1119 {
1120         struct dentry *root;
1121         struct vfsmount *mnt;
1122         char *newargs;
1123
1124         newargs = setup_root_args(data);
1125         if (!newargs)
1126                 return ERR_PTR(-ENOMEM);
1127         mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
1128                              newargs);
1129         kfree(newargs);
1130         if (IS_ERR(mnt))
1131                 return ERR_CAST(mnt);
1132
1133         root = mount_subtree(mnt, subvol_name);
1134
1135         if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
1136                 struct super_block *s = root->d_sb;
1137                 dput(root);
1138                 root = ERR_PTR(-EINVAL);
1139                 deactivate_locked_super(s);
1140                 printk(KERN_ERR "BTRFS: '%s' is not a valid subvolume\n",
1141                                 subvol_name);
1142         }
1143
1144         return root;
1145 }
1146
1147 /*
1148  * Find a superblock for the given device / mount point.
1149  *
1150  * Note:  This is based on get_sb_bdev from fs/super.c with a few additions
1151  *        for multiple device setup.  Make sure to keep it in sync.
1152  */
1153 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1154                 const char *device_name, void *data)
1155 {
1156         struct block_device *bdev = NULL;
1157         struct super_block *s;
1158         struct dentry *root;
1159         struct btrfs_fs_devices *fs_devices = NULL;
1160         struct btrfs_fs_info *fs_info = NULL;
1161         fmode_t mode = FMODE_READ;
1162         char *subvol_name = NULL;
1163         u64 subvol_objectid = 0;
1164         int error = 0;
1165
1166         if (!(flags & MS_RDONLY))
1167                 mode |= FMODE_WRITE;
1168
1169         error = btrfs_parse_early_options(data, mode, fs_type,
1170                                           &subvol_name, &subvol_objectid,
1171                                           &fs_devices);
1172         if (error) {
1173                 kfree(subvol_name);
1174                 return ERR_PTR(error);
1175         }
1176
1177         if (subvol_name) {
1178                 root = mount_subvol(subvol_name, flags, device_name, data);
1179                 kfree(subvol_name);
1180                 return root;
1181         }
1182
1183         error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1184         if (error)
1185                 return ERR_PTR(error);
1186
1187         /*
1188          * Setup a dummy root and fs_info for test/set super.  This is because
1189          * we don't actually fill this stuff out until open_ctree, but we need
1190          * it for searching for existing supers, so this lets us do that and
1191          * then open_ctree will properly initialize everything later.
1192          */
1193         fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1194         if (!fs_info)
1195                 return ERR_PTR(-ENOMEM);
1196
1197         fs_info->fs_devices = fs_devices;
1198
1199         fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1200         fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1201         if (!fs_info->super_copy || !fs_info->super_for_commit) {
1202                 error = -ENOMEM;
1203                 goto error_fs_info;
1204         }
1205
1206         error = btrfs_open_devices(fs_devices, mode, fs_type);
1207         if (error)
1208                 goto error_fs_info;
1209
1210         if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1211                 error = -EACCES;
1212                 goto error_close_devices;
1213         }
1214
1215         bdev = fs_devices->latest_bdev;
1216         s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1217                  fs_info);
1218         if (IS_ERR(s)) {
1219                 error = PTR_ERR(s);
1220                 goto error_close_devices;
1221         }
1222
1223         if (s->s_root) {
1224                 btrfs_close_devices(fs_devices);
1225                 free_fs_info(fs_info);
1226                 if ((flags ^ s->s_flags) & MS_RDONLY)
1227                         error = -EBUSY;
1228         } else {
1229                 char b[BDEVNAME_SIZE];
1230
1231                 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1232                 btrfs_sb(s)->bdev_holder = fs_type;
1233                 error = btrfs_fill_super(s, fs_devices, data,
1234                                          flags & MS_SILENT ? 1 : 0);
1235         }
1236
1237         root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1238         if (IS_ERR(root))
1239                 deactivate_locked_super(s);
1240
1241         return root;
1242
1243 error_close_devices:
1244         btrfs_close_devices(fs_devices);
1245 error_fs_info:
1246         free_fs_info(fs_info);
1247         return ERR_PTR(error);
1248 }
1249
1250 static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit)
1251 {
1252         spin_lock_irq(&workers->lock);
1253         workers->max_workers = new_limit;
1254         spin_unlock_irq(&workers->lock);
1255 }
1256
1257 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1258                                      int new_pool_size, int old_pool_size)
1259 {
1260         if (new_pool_size == old_pool_size)
1261                 return;
1262
1263         fs_info->thread_pool_size = new_pool_size;
1264
1265         btrfs_info(fs_info, "resize thread pool %d -> %d",
1266                old_pool_size, new_pool_size);
1267
1268         btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size);
1269         btrfs_set_max_workers(&fs_info->workers, new_pool_size);
1270         btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size);
1271         btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size);
1272         btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size);
1273         btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
1274         btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size);
1275         btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size);
1276         btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size);
1277         btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size);
1278         btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size);
1279         btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size);
1280         btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size);
1281         btrfs_set_max_workers(&fs_info->scrub_wr_completion_workers,
1282                               new_pool_size);
1283 }
1284
1285 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1286 {
1287         set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1288 }
1289
1290 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1291                                        unsigned long old_opts, int flags)
1292 {
1293         if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1294             (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1295              (flags & MS_RDONLY))) {
1296                 /* wait for any defraggers to finish */
1297                 wait_event(fs_info->transaction_wait,
1298                            (atomic_read(&fs_info->defrag_running) == 0));
1299                 if (flags & MS_RDONLY)
1300                         sync_filesystem(fs_info->sb);
1301         }
1302 }
1303
1304 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1305                                          unsigned long old_opts)
1306 {
1307         /*
1308          * We need cleanup all defragable inodes if the autodefragment is
1309          * close or the fs is R/O.
1310          */
1311         if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1312             (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1313              (fs_info->sb->s_flags & MS_RDONLY))) {
1314                 btrfs_cleanup_defrag_inodes(fs_info);
1315         }
1316
1317         clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1318 }
1319
1320 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1321 {
1322         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1323         struct btrfs_root *root = fs_info->tree_root;
1324         unsigned old_flags = sb->s_flags;
1325         unsigned long old_opts = fs_info->mount_opt;
1326         unsigned long old_compress_type = fs_info->compress_type;
1327         u64 old_max_inline = fs_info->max_inline;
1328         u64 old_alloc_start = fs_info->alloc_start;
1329         int old_thread_pool_size = fs_info->thread_pool_size;
1330         unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1331         int ret;
1332
1333         btrfs_remount_prepare(fs_info);
1334
1335         ret = btrfs_parse_options(root, data);
1336         if (ret) {
1337                 ret = -EINVAL;
1338                 goto restore;
1339         }
1340
1341         btrfs_remount_begin(fs_info, old_opts, *flags);
1342         btrfs_resize_thread_pool(fs_info,
1343                 fs_info->thread_pool_size, old_thread_pool_size);
1344
1345         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1346                 goto out;
1347
1348         if (*flags & MS_RDONLY) {
1349                 /*
1350                  * this also happens on 'umount -rf' or on shutdown, when
1351                  * the filesystem is busy.
1352                  */
1353
1354                 /* wait for the uuid_scan task to finish */
1355                 down(&fs_info->uuid_tree_rescan_sem);
1356                 /* avoid complains from lockdep et al. */
1357                 up(&fs_info->uuid_tree_rescan_sem);
1358
1359                 sb->s_flags |= MS_RDONLY;
1360
1361                 btrfs_dev_replace_suspend_for_unmount(fs_info);
1362                 btrfs_scrub_cancel(fs_info);
1363                 btrfs_pause_balance(fs_info);
1364
1365                 ret = btrfs_commit_super(root);
1366                 if (ret)
1367                         goto restore;
1368         } else {
1369                 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
1370                         btrfs_err(fs_info,
1371                                 "Remounting read-write after error is not allowed");
1372                         ret = -EINVAL;
1373                         goto restore;
1374                 }
1375                 if (fs_info->fs_devices->rw_devices == 0) {
1376                         ret = -EACCES;
1377                         goto restore;
1378                 }
1379
1380                 if (fs_info->fs_devices->missing_devices >
1381                      fs_info->num_tolerated_disk_barrier_failures &&
1382                     !(*flags & MS_RDONLY)) {
1383                         btrfs_warn(fs_info,
1384                                 "too many missing devices, writeable remount is not allowed");
1385                         ret = -EACCES;
1386                         goto restore;
1387                 }
1388
1389                 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1390                         ret = -EINVAL;
1391                         goto restore;
1392                 }
1393
1394                 ret = btrfs_cleanup_fs_roots(fs_info);
1395                 if (ret)
1396                         goto restore;
1397
1398                 /* recover relocation */
1399                 ret = btrfs_recover_relocation(root);
1400                 if (ret)
1401                         goto restore;
1402
1403                 ret = btrfs_resume_balance_async(fs_info);
1404                 if (ret)
1405                         goto restore;
1406
1407                 ret = btrfs_resume_dev_replace_async(fs_info);
1408                 if (ret) {
1409                         btrfs_warn(fs_info, "failed to resume dev_replace");
1410                         goto restore;
1411                 }
1412
1413                 if (!fs_info->uuid_root) {
1414                         btrfs_info(fs_info, "creating UUID tree");
1415                         ret = btrfs_create_uuid_tree(fs_info);
1416                         if (ret) {
1417                                 btrfs_warn(fs_info, "failed to create the UUID tree %d", ret);
1418                                 goto restore;
1419                         }
1420                 }
1421                 sb->s_flags &= ~MS_RDONLY;
1422         }
1423 out:
1424         btrfs_remount_cleanup(fs_info, old_opts);
1425         return 0;
1426
1427 restore:
1428         /* We've hit an error - don't reset MS_RDONLY */
1429         if (sb->s_flags & MS_RDONLY)
1430                 old_flags |= MS_RDONLY;
1431         sb->s_flags = old_flags;
1432         fs_info->mount_opt = old_opts;
1433         fs_info->compress_type = old_compress_type;
1434         fs_info->max_inline = old_max_inline;
1435         mutex_lock(&fs_info->chunk_mutex);
1436         fs_info->alloc_start = old_alloc_start;
1437         mutex_unlock(&fs_info->chunk_mutex);
1438         btrfs_resize_thread_pool(fs_info,
1439                 old_thread_pool_size, fs_info->thread_pool_size);
1440         fs_info->metadata_ratio = old_metadata_ratio;
1441         btrfs_remount_cleanup(fs_info, old_opts);
1442         return ret;
1443 }
1444
1445 /* Used to sort the devices by max_avail(descending sort) */
1446 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1447                                        const void *dev_info2)
1448 {
1449         if (((struct btrfs_device_info *)dev_info1)->max_avail >
1450             ((struct btrfs_device_info *)dev_info2)->max_avail)
1451                 return -1;
1452         else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1453                  ((struct btrfs_device_info *)dev_info2)->max_avail)
1454                 return 1;
1455         else
1456         return 0;
1457 }
1458
1459 /*
1460  * sort the devices by max_avail, in which max free extent size of each device
1461  * is stored.(Descending Sort)
1462  */
1463 static inline void btrfs_descending_sort_devices(
1464                                         struct btrfs_device_info *devices,
1465                                         size_t nr_devices)
1466 {
1467         sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1468              btrfs_cmp_device_free_bytes, NULL);
1469 }
1470
1471 /*
1472  * The helper to calc the free space on the devices that can be used to store
1473  * file data.
1474  */
1475 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1476 {
1477         struct btrfs_fs_info *fs_info = root->fs_info;
1478         struct btrfs_device_info *devices_info;
1479         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1480         struct btrfs_device *device;
1481         u64 skip_space;
1482         u64 type;
1483         u64 avail_space;
1484         u64 used_space;
1485         u64 min_stripe_size;
1486         int min_stripes = 1, num_stripes = 1;
1487         int i = 0, nr_devices;
1488         int ret;
1489
1490         nr_devices = fs_info->fs_devices->open_devices;
1491         BUG_ON(!nr_devices);
1492
1493         devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1494                                GFP_NOFS);
1495         if (!devices_info)
1496                 return -ENOMEM;
1497
1498         /* calc min stripe number for data space alloction */
1499         type = btrfs_get_alloc_profile(root, 1);
1500         if (type & BTRFS_BLOCK_GROUP_RAID0) {
1501                 min_stripes = 2;
1502                 num_stripes = nr_devices;
1503         } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1504                 min_stripes = 2;
1505                 num_stripes = 2;
1506         } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1507                 min_stripes = 4;
1508                 num_stripes = 4;
1509         }
1510
1511         if (type & BTRFS_BLOCK_GROUP_DUP)
1512                 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1513         else
1514                 min_stripe_size = BTRFS_STRIPE_LEN;
1515
1516         list_for_each_entry(device, &fs_devices->devices, dev_list) {
1517                 if (!device->in_fs_metadata || !device->bdev ||
1518                     device->is_tgtdev_for_dev_replace)
1519                         continue;
1520
1521                 avail_space = device->total_bytes - device->bytes_used;
1522
1523                 /* align with stripe_len */
1524                 do_div(avail_space, BTRFS_STRIPE_LEN);
1525                 avail_space *= BTRFS_STRIPE_LEN;
1526
1527                 /*
1528                  * In order to avoid overwritting the superblock on the drive,
1529                  * btrfs starts at an offset of at least 1MB when doing chunk
1530                  * allocation.
1531                  */
1532                 skip_space = 1024 * 1024;
1533
1534                 /* user can set the offset in fs_info->alloc_start. */
1535                 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1536                     device->total_bytes)
1537                         skip_space = max(fs_info->alloc_start, skip_space);
1538
1539                 /*
1540                  * btrfs can not use the free space in [0, skip_space - 1],
1541                  * we must subtract it from the total. In order to implement
1542                  * it, we account the used space in this range first.
1543                  */
1544                 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1545                                                      &used_space);
1546                 if (ret) {
1547                         kfree(devices_info);
1548                         return ret;
1549                 }
1550
1551                 /* calc the free space in [0, skip_space - 1] */
1552                 skip_space -= used_space;
1553
1554                 /*
1555                  * we can use the free space in [0, skip_space - 1], subtract
1556                  * it from the total.
1557                  */
1558                 if (avail_space && avail_space >= skip_space)
1559                         avail_space -= skip_space;
1560                 else
1561                         avail_space = 0;
1562
1563                 if (avail_space < min_stripe_size)
1564                         continue;
1565
1566                 devices_info[i].dev = device;
1567                 devices_info[i].max_avail = avail_space;
1568
1569                 i++;
1570         }
1571
1572         nr_devices = i;
1573
1574         btrfs_descending_sort_devices(devices_info, nr_devices);
1575
1576         i = nr_devices - 1;
1577         avail_space = 0;
1578         while (nr_devices >= min_stripes) {
1579                 if (num_stripes > nr_devices)
1580                         num_stripes = nr_devices;
1581
1582                 if (devices_info[i].max_avail >= min_stripe_size) {
1583                         int j;
1584                         u64 alloc_size;
1585
1586                         avail_space += devices_info[i].max_avail * num_stripes;
1587                         alloc_size = devices_info[i].max_avail;
1588                         for (j = i + 1 - num_stripes; j <= i; j++)
1589                                 devices_info[j].max_avail -= alloc_size;
1590                 }
1591                 i--;
1592                 nr_devices--;
1593         }
1594
1595         kfree(devices_info);
1596         *free_bytes = avail_space;
1597         return 0;
1598 }
1599
1600 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1601 {
1602         struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1603         struct btrfs_super_block *disk_super = fs_info->super_copy;
1604         struct list_head *head = &fs_info->space_info;
1605         struct btrfs_space_info *found;
1606         u64 total_used = 0;
1607         u64 total_free_data = 0;
1608         int bits = dentry->d_sb->s_blocksize_bits;
1609         __be32 *fsid = (__be32 *)fs_info->fsid;
1610         int ret;
1611
1612         /* holding chunk_muext to avoid allocating new chunks */
1613         mutex_lock(&fs_info->chunk_mutex);
1614         rcu_read_lock();
1615         list_for_each_entry_rcu(found, head, list) {
1616                 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1617                         total_free_data += found->disk_total - found->disk_used;
1618                         total_free_data -=
1619                                 btrfs_account_ro_block_groups_free_space(found);
1620                 }
1621
1622                 total_used += found->disk_used;
1623         }
1624         rcu_read_unlock();
1625
1626         buf->f_namelen = BTRFS_NAME_LEN;
1627         buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1628         buf->f_bfree = buf->f_blocks - (total_used >> bits);
1629         buf->f_bsize = dentry->d_sb->s_blocksize;
1630         buf->f_type = BTRFS_SUPER_MAGIC;
1631         buf->f_bavail = total_free_data;
1632         ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1633         if (ret) {
1634                 mutex_unlock(&fs_info->chunk_mutex);
1635                 return ret;
1636         }
1637         buf->f_bavail += total_free_data;
1638         buf->f_bavail = buf->f_bavail >> bits;
1639         mutex_unlock(&fs_info->chunk_mutex);
1640
1641         /* We treat it as constant endianness (it doesn't matter _which_)
1642            because we want the fsid to come out the same whether mounted
1643            on a big-endian or little-endian host */
1644         buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1645         buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1646         /* Mask in the root object ID too, to disambiguate subvols */
1647         buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1648         buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1649
1650         return 0;
1651 }
1652
1653 static void btrfs_kill_super(struct super_block *sb)
1654 {
1655         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1656         kill_anon_super(sb);
1657         free_fs_info(fs_info);
1658 }
1659
1660 static struct file_system_type btrfs_fs_type = {
1661         .owner          = THIS_MODULE,
1662         .name           = "btrfs",
1663         .mount          = btrfs_mount,
1664         .kill_sb        = btrfs_kill_super,
1665         .fs_flags       = FS_REQUIRES_DEV,
1666 };
1667 MODULE_ALIAS_FS("btrfs");
1668
1669 /*
1670  * used by btrfsctl to scan devices when no FS is mounted
1671  */
1672 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1673                                 unsigned long arg)
1674 {
1675         struct btrfs_ioctl_vol_args *vol;
1676         struct btrfs_fs_devices *fs_devices;
1677         int ret = -ENOTTY;
1678
1679         if (!capable(CAP_SYS_ADMIN))
1680                 return -EPERM;
1681
1682         vol = memdup_user((void __user *)arg, sizeof(*vol));
1683         if (IS_ERR(vol))
1684                 return PTR_ERR(vol);
1685
1686         switch (cmd) {
1687         case BTRFS_IOC_SCAN_DEV:
1688                 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1689                                             &btrfs_fs_type, &fs_devices);
1690                 break;
1691         case BTRFS_IOC_DEVICES_READY:
1692                 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1693                                             &btrfs_fs_type, &fs_devices);
1694                 if (ret)
1695                         break;
1696                 ret = !(fs_devices->num_devices == fs_devices->total_devices);
1697                 break;
1698         }
1699
1700         kfree(vol);
1701         return ret;
1702 }
1703
1704 static int btrfs_freeze(struct super_block *sb)
1705 {
1706         struct btrfs_trans_handle *trans;
1707         struct btrfs_root *root = btrfs_sb(sb)->tree_root;
1708
1709         trans = btrfs_attach_transaction_barrier(root);
1710         if (IS_ERR(trans)) {
1711                 /* no transaction, don't bother */
1712                 if (PTR_ERR(trans) == -ENOENT)
1713                         return 0;
1714                 return PTR_ERR(trans);
1715         }
1716         return btrfs_commit_transaction(trans, root);
1717 }
1718
1719 static int btrfs_unfreeze(struct super_block *sb)
1720 {
1721         return 0;
1722 }
1723
1724 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1725 {
1726         struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1727         struct btrfs_fs_devices *cur_devices;
1728         struct btrfs_device *dev, *first_dev = NULL;
1729         struct list_head *head;
1730         struct rcu_string *name;
1731
1732         mutex_lock(&fs_info->fs_devices->device_list_mutex);
1733         cur_devices = fs_info->fs_devices;
1734         while (cur_devices) {
1735                 head = &cur_devices->devices;
1736                 list_for_each_entry(dev, head, dev_list) {
1737                         if (dev->missing)
1738                                 continue;
1739                         if (!first_dev || dev->devid < first_dev->devid)
1740                                 first_dev = dev;
1741                 }
1742                 cur_devices = cur_devices->seed;
1743         }
1744
1745         if (first_dev) {
1746                 rcu_read_lock();
1747                 name = rcu_dereference(first_dev->name);
1748                 seq_escape(m, name->str, " \t\n\\");
1749                 rcu_read_unlock();
1750         } else {
1751                 WARN_ON(1);
1752         }
1753         mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1754         return 0;
1755 }
1756
1757 static const struct super_operations btrfs_super_ops = {
1758         .drop_inode     = btrfs_drop_inode,
1759         .evict_inode    = btrfs_evict_inode,
1760         .put_super      = btrfs_put_super,
1761         .sync_fs        = btrfs_sync_fs,
1762         .show_options   = btrfs_show_options,
1763         .show_devname   = btrfs_show_devname,
1764         .write_inode    = btrfs_write_inode,
1765         .alloc_inode    = btrfs_alloc_inode,
1766         .destroy_inode  = btrfs_destroy_inode,
1767         .statfs         = btrfs_statfs,
1768         .remount_fs     = btrfs_remount,
1769         .freeze_fs      = btrfs_freeze,
1770         .unfreeze_fs    = btrfs_unfreeze,
1771 };
1772
1773 static const struct file_operations btrfs_ctl_fops = {
1774         .unlocked_ioctl  = btrfs_control_ioctl,
1775         .compat_ioctl = btrfs_control_ioctl,
1776         .owner   = THIS_MODULE,
1777         .llseek = noop_llseek,
1778 };
1779
1780 static struct miscdevice btrfs_misc = {
1781         .minor          = BTRFS_MINOR,
1782         .name           = "btrfs-control",
1783         .fops           = &btrfs_ctl_fops
1784 };
1785
1786 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1787 MODULE_ALIAS("devname:btrfs-control");
1788
1789 static int btrfs_interface_init(void)
1790 {
1791         return misc_register(&btrfs_misc);
1792 }
1793
1794 static void btrfs_interface_exit(void)
1795 {
1796         if (misc_deregister(&btrfs_misc) < 0)
1797                 printk(KERN_INFO "BTRFS: misc_deregister failed for control device\n");
1798 }
1799
1800 static void btrfs_print_info(void)
1801 {
1802         printk(KERN_INFO "Btrfs loaded"
1803 #ifdef CONFIG_BTRFS_DEBUG
1804                         ", debug=on"
1805 #endif
1806 #ifdef CONFIG_BTRFS_ASSERT
1807                         ", assert=on"
1808 #endif
1809 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1810                         ", integrity-checker=on"
1811 #endif
1812                         "\n");
1813 }
1814
1815 static int btrfs_run_sanity_tests(void)
1816 {
1817         int ret;
1818
1819         ret = btrfs_init_test_fs();
1820         if (ret)
1821                 return ret;
1822
1823         ret = btrfs_test_free_space_cache();
1824         if (ret)
1825                 goto out;
1826         ret = btrfs_test_extent_buffer_operations();
1827         if (ret)
1828                 goto out;
1829         ret = btrfs_test_extent_io();
1830         if (ret)
1831                 goto out;
1832         ret = btrfs_test_inodes();
1833 out:
1834         btrfs_destroy_test_fs();
1835         return ret;
1836 }
1837
1838 static int __init init_btrfs_fs(void)
1839 {
1840         int err;
1841
1842         err = btrfs_init_sysfs();
1843         if (err)
1844                 return err;
1845
1846         btrfs_init_compress();
1847
1848         err = btrfs_init_cachep();
1849         if (err)
1850                 goto free_compress;
1851
1852         err = extent_io_init();
1853         if (err)
1854                 goto free_cachep;
1855
1856         err = extent_map_init();
1857         if (err)
1858                 goto free_extent_io;
1859
1860         err = ordered_data_init();
1861         if (err)
1862                 goto free_extent_map;
1863
1864         err = btrfs_delayed_inode_init();
1865         if (err)
1866                 goto free_ordered_data;
1867
1868         err = btrfs_auto_defrag_init();
1869         if (err)
1870                 goto free_delayed_inode;
1871
1872         err = btrfs_delayed_ref_init();
1873         if (err)
1874                 goto free_auto_defrag;
1875
1876         err = btrfs_prelim_ref_init();
1877         if (err)
1878                 goto free_prelim_ref;
1879
1880         err = btrfs_interface_init();
1881         if (err)
1882                 goto free_delayed_ref;
1883
1884         btrfs_init_lockdep();
1885
1886         btrfs_print_info();
1887
1888         err = btrfs_run_sanity_tests();
1889         if (err)
1890                 goto unregister_ioctl;
1891
1892         err = register_filesystem(&btrfs_fs_type);
1893         if (err)
1894                 goto unregister_ioctl;
1895
1896         return 0;
1897
1898 unregister_ioctl:
1899         btrfs_interface_exit();
1900 free_prelim_ref:
1901         btrfs_prelim_ref_exit();
1902 free_delayed_ref:
1903         btrfs_delayed_ref_exit();
1904 free_auto_defrag:
1905         btrfs_auto_defrag_exit();
1906 free_delayed_inode:
1907         btrfs_delayed_inode_exit();
1908 free_ordered_data:
1909         ordered_data_exit();
1910 free_extent_map:
1911         extent_map_exit();
1912 free_extent_io:
1913         extent_io_exit();
1914 free_cachep:
1915         btrfs_destroy_cachep();
1916 free_compress:
1917         btrfs_exit_compress();
1918         btrfs_exit_sysfs();
1919         return err;
1920 }
1921
1922 static void __exit exit_btrfs_fs(void)
1923 {
1924         btrfs_destroy_cachep();
1925         btrfs_delayed_ref_exit();
1926         btrfs_auto_defrag_exit();
1927         btrfs_delayed_inode_exit();
1928         btrfs_prelim_ref_exit();
1929         ordered_data_exit();
1930         extent_map_exit();
1931         extent_io_exit();
1932         btrfs_interface_exit();
1933         unregister_filesystem(&btrfs_fs_type);
1934         btrfs_exit_sysfs();
1935         btrfs_cleanup_fs_uuids();
1936         btrfs_exit_compress();
1937 }
1938
1939 module_init(init_btrfs_fs)
1940 module_exit(exit_btrfs_fs)
1941
1942 MODULE_LICENSE("GPL");